Gunn serves as a mentor to the aspiring designers on the series, as well as on the spinoff Project Runway: Junior. And apparently, he's much more fond of the Junior judges than the ones on the original show.

In the Stuff interview, Gunn praised the Project Runway: Junior judges, who include Christian Siriano, Hannah Jeter, Aya Kanai, and Kelly Osbourne. "Their voices are measured and thoughtful — and honest," Gunn said of the Junior judges. Meanwhile, he suggested that the regular Project Runway judges, who include Heidi Klum, Nina Garcia, and Zach Posen, are too "mean-spirited."

"I am sick of our regular season judges and their attempts to outwit each other and come up with a remark they think is adorable and cute but which is, in fact, piercing and mean-spirited," Gunn told Stuff. "I don't like it. I find it to be very unprofessional and offensive."

It's not just the judges who upset Gunn, either. He suggested that some designers are more interested in fame than in succeeding in the fashion industry."I have to say this — the adults, some of them, they want to be TV characters, and once they arrive it would appear that that's why they're really there," Gunn told Stuff of the Project Runway contestants.

Gunn also explained that Season 13 was his favorite, because "there were no games, there was no unnecessary drama, and all the designers wanted to do was create the best work possible."

And while he was skeptical about working with teens, it looks like Gunn finds them more responsible than many of the adult contestants.

"I'd had very, very little experience working with younger people, but I have to tell you, I love it so much that if I had to choose between regular Runway and Project Runway Junior, I would choose Junior in a heartbeat," Gunn told Stuff. "They listen, they take responsibility for their actions, they're not blaming anyone else, they are very professional in their behavior and their decorum, and they're not backbiting or being snarky or nasty about things."

Gunn's statements make total sense — of course designers would respond better to feedback that's not dripping with sarcasm or overt meanness. But thoughtful critiques don't always make for great reality TV.